Fixed wing flying drones correspond to drones driven by motors, and that comprise a wing that provides sufficient lift for the drone to fly, starting from a predetermined drone displacement speed. These “fixed wing” flying drones are in contrast with “rotating wing” flying drones for which lift is provided by one or several rotors.
Flying devices of this type may be small or large and propelled by different types of motor drives.
Drones equipped with a motor drive using electricity have the advantages of long endurance. For example, prior art discloses such drones designed to fly for a long period at high or medium altitude.
Electrical accumulators and photoelectric cells are used to supply electrical power to these drones. During the day, the photovoltaic cells are dedicated to the electrical power supply of the drone and to recharging the electrical accumulators. The electrical accumulators take over at night, so that the drone can continue to fly until the photovoltaic cells are once again exposed to sunshine.
Prior art discloses solutions for improving the endurance and load carrying capacity of a drone, by storing electrical energy collected from sunshine.
Thus, there are drones with a single fuselage and one supporting wing, covered with photovoltaic cells, with a very long wingspan relative to the length of the drone.
There are also drones with a plurality of fuselages arranged in parallel, supporting a long wingspan, the fuselages and the wing being covered entirely by photovoltaic cells.
This also includes flying drones with oversized devices so as to increase the drone area that can be covered with photovoltaic cells. Flying drones exist with an oversized tail fin.
These different solutions can increase the surface area of an aircraft on which photovoltaic cells can be coupled. However, these solutions induce many disadvantages.
Firstly, some drone architectures cause high structural stresses when the drone is in flight. These structural stresses may be the result of an excessive wingspan and require the use of high technicity composite materials. The structural stresses of these architectures are then accompanied by a large wingspan and a high manufacturing cost of flying drones.
Secondly, there are architectures that lead to bad placement of photovoltaic cells relative to the structural elements of the flying drone, consequently reducing the global sunshine to which photovoltaic cells coupled on this drone are exposed. For example, it is observed that architectures using multiple fuselages can create shadow zones on drone surfaces on which photovoltaic cells are installed. Therefore such architectures are prejudicial to the extent to which photovoltaic cells can be exposed to sunshine, even though these same photovoltaic cells add weight to the flying drone. Thus, there is a degradation to the performances and endurance of the flying drone designed with one of these architectures.